Differences in Surface Water Quality Draining Four Road Surface Types in the Southern Appalachians

Improved and unimproved roads can be the primary source of stream sediment in forested watersheds . We assessed dif ferences in product ion of to ta l suspended solia!s (TSS; ppm) f rom four road sulfate condit ions in a Southern Appalachian watershed: (1) a 2-yr-oldpaved surface (P) , (2) an improvedgravel sulfate with control leddrainage and rout ine maintenance (RG), (3) an improvedgravel surjace with erosion andsediment control s tructures ins tal led and rout ine maintenance (IG}, and (4) an unimproved poorly maintained gravel surface (UG). Variat ion was high among and wi thin road sulfate types. The P surface generated the least amount of TSS, which was comparable to control s i tes , while the UG surjace generated the most . The P surface produced signij?cantly less TSS than the UG sudace, but not less than the IGandRGsulfaces. Variation among roads&ace types was re la ted to TSS travel d is tance be low the road, prec ip i ta t ion amount , t ime of year, and the existence of funct ioning erosion and sediment control s tructures . TSS decreased wi th travel d is tance (P = -81% over 38.5 m, IG = -30% over 30.5 m, RG = -89% over 39.4 m, and UG = -22% over 28. I m) . Also in this s tudy we assessed the del ivery of to ta l pe tro leum hydrocarbons (TPH; ppm)from the P surface andfoundconcentrat ions of < OSppm, which are well below published USEPA andNCDENR TPHstandardsforsediment. Paving isan a t t rac t i ve op t ion for reducing maintenance costs and sediment product ion and transport; however , levels of TPH from freshly applied asphalt are unknown. South. J. Appl . For. 27(2):10&106.